High humidity favours the proliferation of a wide range of weed species. Studying the phytosociological attributes of weeds in a humid area provides insight into the dynamism and relative importance of each weed species peculiar to the area which is very important in understanding crop-weed interrelationships and highlights the bases for effective management stratages. An experiment was conducted in 2019 and 2020 cropping seasons at the Department of Crop Science Teaching and Research Farm, University of Calabar, to identify the predominant weeds in the farm area and assess their responses to polyethylene colour and soil solarization duration. The experiment was a factorial combination of two polyethylene colour (black and transparent) and five in situ soil solarization durations (0, 8, 12, 16 and 48 weeks), laid out in randomized complete block design (RCBD) with three replications. Data were collected on the phytosociological characteristics of the weeds on four weekly intervals up to the twentieth week. The predominant weeds identified in the experimental area were Eragrostis ciliaris L., Cynodoon dactylon L., Panicum maximum Jacq., Axonopus compressus Beav., Kyllinga bulbosa Beav. and Kyllinga erecta Schum., Gloriosa superba L., Ipomoea involuncrata P., Calapogonium mucunoides Desv., Aspillia bussei O. Hoff, Ageratum conyzoides L., Phyllantus amarus Schum., Caldum bicolor Vent., Triumfeta rhomboidea Jacq., Cleome rutidosperma DC., Euphorbia heterophylla L., Mitracarpos villosus DC., Oldenladia. herbacea L. The relative density of Caladum bicolor was higher across the treatment in both years, reaching up to 37.7 % in the plot solarized for 16 weeks using black polyethylene, followed by P. maximum with upto 18.40 % in 2019 and Gloriosa superba (20.50 %) in 2020. The highest Important Value Index was recorded by Caladum bicolor reaching up to 28.7 % in the plot solarized for 16 weeks using black polyethylene. The lowest species variation was recorded in the plots solarized for 16 to 48 weeks irrespective of the polyethylene colour. In situ solarization of up to sixteen weeks using black polyethylene effectively controlled majority of the weed species in both years and is recommended for effective weed suppression in cassava farms in humid environment.

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Agronomic characterization of 'Ikom White' maize (Zea mays L.

Field experiments were conducted in 2012 and 2013 at the Teaching and Research Farm of the University of Calabar, Cross River State, Nigeria to determine the effectiveness of integration of Fitsextra® (a solution containing Atrazine and Metolachlor herbicides as active ingredients), egusi melon and hand-weeding on weed management and tuber yield of cassava. The twelve treatments which involved individual and combinations of the above-mentioned weed control methods were laid out in a randomized complete block design and replicated three times. Irrespective of the method adopted, weeding depressed weed density by 57.33 % and 63.99 % in 2012 and 2013, respectively and weed biomass by 81.00 % and 79.64 % within the same period compared with the unweeded check. Integration of Fitsextra with egusi melon and/or handweeding significantly (P<0.05) suppressed weeds more than the sole use of Fitsextra® or egusi melon. Integration of hand-weeding with Fitsextra and/or egusi melon reduced weed dry matter by 43.46, 87.25, 92.34 and 93.51 % in 2012, and by 53.20, 90.20, 94.61 and 94.56 % in 2013 compared with handweeding alone, Fitsextra alone, egusi melon alone and no weeding, respectively. Plots that were hand-weeded thrice and those treated with Fitsextra + handweeding twice significantly (P<0.05) produced the highest fresh tuber yield of 9.73 and 10.23 t/ha, respectively in 2013. No weeding reduced cassava tuber yield by 4.83 t/ha (84.89 %) on a 2-year average, compared with the weeded plots. Conclusively, the results indicated that, three hand-weeding optimized cassava tuber yield, however, the integration of Fitsextra or egusi melon can effectively replace the first hand-weeding.